Human ancestors scrambled to their feet, a new explanation for bipedalism asserts

By Erin Wayman, 10:13 AM July 1, 2013

WHOOSH. Scrambler Man ascends steep cliffs in a single burst, leaving his barbaric enemies in the dust. Then, while chasing angry beasts uphill and down, Scrambler Man is transformed into — POOF — The Biped, who can outwalk, outlast and outsmart them all.

Scrambler Man and The Biped could be a weird comic book superhero tale, but it’s really a different kind of story about how humans came to be: A group of researchers proposes that maneuvering in rough, rugged terrain drove the evolution of up...